In low-mass single-star evolution an LTP (when hydrogen still burns in a thin shell) or a VLTP (after the hydrogen burning has ceased) take place when the helium mass on top of the CO core when the star leaves the AGB is \(\Delta M_{\rm He} \simeq 0.01 M_\odot \)  (e.g., [1]}, [2]}). On the other hand, more massive stars, super-AGB stars that form oxygen-neon cores, have weak thermal pulses with short time intervals between pulses (e.g., [3]}; see discussion of thermal pulses by, e.g., [4]}). This implies that only a small hydrogen mass is required to lead to the next pulse. [3]} finds that for a core of about \(1.3 M_\odot \)  the hydrogen mass advances by only \(5 \times 10^{-5} M_\odot \)  between pulses. Two comments related to these values are as follows. (1) The young merger product is more extended than an isolated massive WD of the same mass [6]}, and so the required mass for a LTP/VLTP is larger than for a single star of the same mass. (2) The relevant point for this study is that if the LTP/VLTP is very weak, lasts for a short time, and does not contain much mass, then it has only a minor effect on the light curve of the SN Ia.
